Among the top complaints by frustrated punters on the site were issues with the sound quality, rubbish being strewn all over the floor, excessive lines for bars, food stalls and toilets, and an “unsafe” lack of security.

It’s claimed there was not enough security patrolling the ‘all ages’ event.Source:Facebook

Other users in the Facebook group were furious that their view of the stage was obstructed.Source:Facebook

One angry attendee wrote in the Facebook group that the audio quality was “embarrassing to listen to”.

“It is clear that from the organisers, to the promoters to the hosts, no one has done their job efficiently and effectively,” Kelly Rebecca said.

“I have been to many concerts and events in my life to be able to compare this to those of my past and this was a downright disgrace.”

Emerald Esther Black described it as the “worst concert ever”.

“We had travelled from interstate thinking it was going to be the best. We where pack (sic) in like sardines, people pushing and shoving, drunks fighting … Security was an absolute joke. We definitely won’t be attending again. Waste of my time and money.”

Meanwhile, Katia Panzera vented her frustration at being left “hugely disappointed”.

“I have been waiting a real long time for Usher to return to Melbourne, after Saturday’s event I feel robbed of the experience! We paid $183 per ticket x9 of us and could barely see him. The stage was too far, it struck me when we were there that it didn’t matter where you were sitting there was no way you could see the artists. The lighting was shocking, the sound was terrible! Even the screens were shocking!”

In a statement to news.com.au, RnB Fridays Live said: “We appreciate the feedback we have received with regards to RNB Fridays Live event that was held at Marvel Stadium, Melbourne on Saturday 10 November.

“While some of the concerns raised were addressed on the night, we understand that some of our guests remain dissatisfied by their experience. We are currently in conversation with Marvel Stadium with regards to comments we have received about the length of queues and the state of the venue facilities.

“Please be assured your feedback is valued and we are working through the communications we have received. To streamline the process we ask for any complaints to please be addressed to RNB Fridays Live at feedback@rnbfridayslive.com ”

Frontier Touring, who are the organisers of RnB Fridays Live, also told news.com.au that they and Marvel Stadium are “currently in the process of working through complaints that were received following the Melbourne concert”.

“On the night of the Melbourne event, our team worked hard to deal with the issues raised by our guests, with considerable success. We are, however, incredibly disappointed that the event did not run as smoothly as it has historically or to the high standards our collective businesses believe appropriate,” a spokeswoman said.

“We recognise that some of our guests remain dissatisfied by their experience and a small percentage of the 51,000 fans in attendance have since contacted us to express their disappointment.

“We take their feedback very seriously and intend to respond to each of these complaints properly when we have had the opportunity to conduct a comprehensive review of the night.”